Method of making gas.



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yMIEIIIIR'Y A: CARPENTER, OF SEWICKLEY, PENNSYLVANIA, ASSIGNOR TO RTER-CNIEY MANUFACTURING COMPANY, F PITTSBURGH, PENNSYLVANIA, A CORPORATION or New Jnnsnv.

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Specification of Letters Patent.

METHOD OF MAKING- GAS.

.patented nee. es, isis.

To all whom it may concern Be it known that I, HENRY A. CARPENTER,

`a citizen of the United States, residing at lSewickley, in the county of Allegheny and State of Pennsylvania, have invented certain` new and useful Improvements in Methods of Making Gas, of which the following is a specification.

My invention relates to the manufacture of gas, and more particularly to the manufacture of coal-gas by the distillation lof coal placed within the retorts of a gas-bench, and'distilled therein by the employment of gas generated in a gasproducer connected with the bench.

In the operation of apparatus of the class mentioned as'heretofore practised, considerable trouble has arisen by reason of the co-mbiistion gas, that is lto say, the gas' employed for heating the retorts, mixing with the retort orilluminating gas. This mixing is caused either by an excess of pressure within the-retorts causing the-.gas therein to 'leak through-the walls .ofgthe'l retort and mix with .25 Ithe combustion ga goriion the other hand, byanexcess of ssure in the combustion chamber which forces producer gas into the retortsp- Heretofore, considerable pressure hasl accumulated in the combustion chamber, particularly in the upper portion thereof, the pressure at times being considerably in excess of the pressure vwithin the retorts.

Apparatus of the character above outlined as ,heretofore commercially confstructed, -may be divided into two classes.

The apparatus of the first class includes -a comparatively low gas bench of not more than three, or at the greatest four, retorts high, and in which the illuminatingpr retort gas is taken 0E frointhe respective retorts by means ofindividua'l pipes in direct communication4 with the respective retorts of the gas bench, said, pipes having considerable length and of rather small cross# t5 sectional area. l I lln the operation of the apparatus of the rst class', the pressure in a retort immediately after the retort has been freshly charged and at which time the make ofgas 5U is'. very rapid, is considerably increased,

being higher than the average pressure during the distillation periods. This increase of pressure within the freshly charged retorts tends to `force 'some of the gas out 'hh through `the wallsof vthe retorts and by de-A positing carbon thereon closes the cracks, thus having a tendency to prevent leakage of the combustion gas into the retorts even though the pressure on the outside of the retorts is somewhat greater than the pressure within'.

ln the apparatus of the second class, the gas bench is built high and contains as many as eight to ten supei'posed retorts. This apparatus of the second class is also distinguished from theapparatus of the first class Y in that the gas /is discharged from the retorts in. such a manner as to prevent any considerable rise in pressure over the desired operating pressure, even at the time the retort is freshly charged, so that the rise of pressure within the retort or retorts will not v y be sufficient to force the gas through the retort walls into the combustion chamber and deposit carbon in the cracks, the consequence being that should the pressure within the combustion chamber or on the outside of the retorts become greater than the pressure within the retorts, the combustion gas will leak through and mix with the illuminating or retortl gas.`

My invention particularly relates to the operation of apparatus under the second class, and the prime object is to provide a new and improved method of operating gas generating apparatus whereby the mingling or mixing of the retort and combustion gases is prevented.

A further object is to provide a method of operating whereby the pressure in the retort chamber, combustion chamber or space surrounding the retoits may be maintained' at all times below retort pressure, with the pressure within each retort maintained substantially constant and preferably, though not necessarily, below atmospheric pressure.'

The gas pressure inthe combustion chamber is greatest in the upper portion thereof so that the higher the retorts the greater the external pressure thereon. The approximate difference in pressure between retorts spaced twenty-five inches from center to center is .035 inches water gage. It is my 'purpose to preferably maintain an external pressure on the topmost retort ofv at 'least .1 inch w'ater gage below atmosphere, although l do not'confineniyself thereto. i

' A further object of the invention is to operate the plant under the pressure conditions stated relatively to the combustion ilo chamber and the retorts, and at the same time regulate. the 'pressure within the producer.

Coal gas generating apparatus suitable for practising` the invention is shown dia- 'grammatically in the accompanying drawing.

In the drawing, 1 designates a gas producer of the usual or any preferred type, 2 a retort chamber, and 3 a recuperator structure interposed between the retort chamber and the producer. Gas generated in the producer is conveyed to the combustion chamber 4 of the retort chamber through a flue or passage 5. As is usual, the gas from the producer is mixed with secondary air introduced through openings 5a, and the combustion gas passed up through the retort chamber and around the retorts 6 therein for the purpose of distilling the coal within the retorts. For the purpose of regulating the pressure within the gas-producer and particularly for maintaining a level gage on the top thereof, I provide a valve 7.

As illustrated, the primary air for supporting combustion in the producer is forced -thereto through a flue 8 by means of a blower 9. The coal gas from the retorts 6 is discharged int-o large stand-pipes l0 disposed in contact with or in close proximity to the retort mouth-pieces 11. Said mouthpieces are each provided with an opening 12 through which the gas enters the standpipe. As illustrated, the retort gas is led upwardly by means of the stand-pipes into a main or chamber 13. 14 designates a conduit in communication with the main 13 at one end and with a pipe 15 at its other end, saidrvpipe 15 being in turn connected with alrfexhauster ldesigned to draw or suck the gas from the retorts and pass it along th ough'the system as is usual in apparatus f this character.

The products; of combustion are Awithdrawn from chamber 2 downwardly through flues or passages 17, 18 by means of an eX- hauster 19 in communication with an enlarged conduit 20, the latter being connected with the passage 18 by means of a connectionr 2l. y

The method of operating the apparatus shown is as follows: The producer is supplied with a bed of ignited fuel in the usual manner, and by means of the fan or blower 9 and the exhauster 19, a current is established through the producer, etcL, theair forced through the flue or passage 8 by the blower 9 reacting with the incandescent fuel and forming producer gas in the usual and Well yknown manner. This producer gas is then' passed to the combustion chambei` 4 of the retort chamber where it is mixed with secondary air and utilized for heating the retorts 6. Under the action of the exhauster19, after passing upwardly4 through the retort chamber the products are drawn down into ilues or passages 1T. 18 into the enlarged conduit 20. In practice, the exhauster 19 is capable of and is operated in such a, manner as to at all times maintain a pressure throughout'the interior 0f the retort chamber lower than retort pressure and preferably below atmospheric pressure. It will. of course, be evident that the pressure within the retort chamber will not be the same throughout its height, being somewhat less near the bottom thereof than near the top. It is my preference howeverto maintain the pressure even at the top of the retort chamber below atmospheric pressure and always below the pressure within the highest retort of the bench.

As here illustrated, the gasv from the retorts is drawn into the stand-pipe by'means of the exhauster 1G, and preferably in such a manner as to maintain the pressure within the retorts below atmospheric pressure, but at the same time to maintain the pressure within a given retort greater than the pressure at the exterior thereof. In other words, the pressure immediately surrounding each retort will be maintained below the pressure within the retort. By this means the passage of producer gas'and products through any cracks in the retort walls (formed of refractory material in the usual manner) is prevented. The higher pressure within the retorts has the eiiect of forcing carbon into and sealing any cracks that may exist, preventing the escape of re-` tort gas into the bench.

l/Vhen, as illustrated, I employ a combined forced draft and suction operated producer in connection with my method of pressure regulation for the retort chamber and the retorts therein, I am enabled to control the pressure conditions within the producer and, for example, mai tain a level gage on the top of the producer.

That I claim is l. In the manufacture of coal gas, the method herein described consisting in placing coal in a retort having walls through which gas may pass, subjecting the retort to coal-carbonizing temperature, and maintaining predetermined pressures at the interior and exterior of the retort.

2. In the manufacture of coal gas, the `method herein described consistiu g in placing coal in a retort having walls through which gas. may pass, heating the retort within a chamber to coal carbonizing temperature by burning gaseous fuel within -such chamber, and r,maintaining predetermined pressures within the combustion 125 chamber and Within the retort with the retort pressure exceeding the combustion chamberspressure.

3. In the manufacture of coal gas, the method herein described consisting in placmedias ing coal in a retort having walls through which gas may pass, subjecting the retort to coal-carbonizing temperature and to 'predetermined v external pressure, and maintaining substantially .uniform pressure within the' retort with such retort pressure in excess of said external pressure.

4. In the .manufacture of coal gas, the

ymethod herein described consisting in placl0' ing'coal in a retort having walls through which gas may pass, heating the retort Withmethod herein described consisting in placi ing coal within' a. retort having walls through which gas-may pass, heating the retort within a chamber to coal-carbonizing temperature, and maintaining different pressure conditions in the lchamber and in the retort with the retort pressure higher than the chamber pressure.

6. In the manufacture of coal gas, the method herein described consisting in placing coal within a retort having walls through lwhichgas may pass, heating the retort within a chamber to coal-carbonizing temperature by burninggaseous fuel within such' chamber, rarifyingthe gaseous fuel and products within the chamber, and maintaining 'a higher but substantially uniform pressure 'within thev retort. y

7. In the manufacture of coal gas,` the method herein described consisting in placing coal within a plurality of retorts lhaving Walls through which gas may pass, heating vall of the retorts within a chamber by burninggaseous fuel within such chamber, rarifyng the gaseous fuel and products within thechamber and thereby subjecting the eX- terior of allthe retorts to less than atmospheric pressure, and maintaining a substantially uniform pressure within all the retorts with` such pressure higher than said chamber pressure.

8. In the manufacture, of coal gas, the method herein described consistingin placing coal Within a plurality of retorts having walls through which gas may pass, heating all the retorts within a chamber to coalcar bonizing temperature, maintaining the interior of the chamber underv suction, main taining communication between the retorts and an offtake common to all of the retorts, and maintaining the oftake under suction.

9. In the manufacture of coal gas, the method herein described consisting in placing coal within a retort 4having walls through which gas-may pass with the retort located in a chamber, malntaining communication between the chamber and the gas outlet of a gas producer, maintaining the chamber under suction and thereb drawing-the gas thereinto from the pro ucer, burning.

the gas and thereby heating the retort to coal-carbonizing temperature, and :main taining a substantially uniform pressure Within the retort throughout the carboniza ,tion period with said pressure higher than the pressure within the retort conining chamber. l

In testimony whereof I affix my signature in presence of two witnesses.

HENRY A. CARPENTER.

Witnesses:

W. G. DooLITTLE, F. E. GAITHER.

Uopies of this patent may be obtained for ve cents'each, by addressing the Commissioner of Patente.

' Washlnmon, D. G. 

